


XO

by mireailles



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alpha/Beta/Omega Dynamics, M/M, Mpreg, modern day AU
Language: English
Status: Completed
Published: 2017-06-30
Updated: 2017-06-30
Packaged: 2018-11-21 08:17:48
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,539
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11353512
Author URL: https://archiveofourown.org/users/mireailles/pseuds/mireailles
Summary: Modern day AU. Omega!Armin/Beta!Jean. You love me like XO.





	XO

**Author's Note:**

> Written for Armin's b-day last year. Might write more ABO Jearmin, considering the lack of it LOL. Oh, also there's like a bit of Eren/Armin in the beginning.

He learns at the age of five that he is different from Eren. It happens when Carla takes them to the pool and leaves them in a changing room by themselves. There’s a few seconds when they stare at each other’s private parts, almost mystified by the differences. It must’ve been longer than any of them realize because Carla pokes her head in and sees the two of them.

She tells Eren to pull his pants back up and to ‘let Armin change alone.’

 

It is the first of many changes that happen within the year. When he sleeps over at Eren’s house, Carla makes sure the two of them are in separate rooms. Eren fights the changes, tooth and claw. Armin tries to understand as much as he can. One day, his grandfather pulls him aside with a book in hand. 

There are pictures in it that are strange and some he recognizes. His grandfather lets him keep the book afterwards, he stares at the pictures long past his bedtime, intrigued.

 

When Armin is ten, he learns the exact same thing that his grandfather has already taught him. Eren looks up at the blackboard as if he’s bored. Armin knows that Eren has already gotten a lecture from both his mother and his father about boundaries with Armin and Mikasa’s been given the same lecture, so it’s not really news to any of them. Their other classmates look uncomfortable at the subject matter, especially the part when the teacher goes into detail on the Omega reproductive system.

The three of them get the highest marks on the test.

 

On Armin’s first heat, his grandfather lets him stay home for the week. Eren and Mikasa visit when he starts spotting but only Carla is allowed with him after the first day. He doesn’t see either of them when his heat takes hold of him but he hears them through his open door. Later, his grandfather gives him soup he is sure Carla has made. The rest of the week passes in a strange thick haze of nausea and strong sexual urges. The only thing that keeps him company is his pillow, blanket and hot-water bottle on his stomach.

 

Eren hugs him when he goes back to school. It’s long and feels different than it did before. There’s still the same feelings of mutual love and something different that makes Armin’s heart skip a beat. He can sense it’s the same for Eren too. Grandpa has said that things will be both different and the same after he starts his heats.

 

High school starts and Armin realizes something about himself: he likes boys. Though he would never admit it out loud, being in the locker room with all the other omegas makes his chest feel tight and his face go red. It’s not like the embarrassment of being the scrawniest and smallest omega in the group, it feels different, Armin can distinguish the difference. It’s nothing compared to how he feels around Eren. When Eren holds him now, there’s a part of Armin that wishes for it to last forever. He stands up on his toes, waiting to see Eren when he picks him up so they can walk to school together. There’s a rush to it, an excitement of just being with him.

He doesn’t know if Eren feels the same way, it’s hard to tell sometimes. Both him and Mikasa help him through his heats now and none of the adults have caught onto it, yet. It’s nice the way the two of them make sure he’s not in any pain when they’re with him all three of their desires being met all at once.

 

At fourteen he gets his wish. He’s all alone, underneath the bleachers with Eren. It’s sunny today and the sunlight filters through the seats. There’s the creaking of the rusted metal when the wind picks up. Eren leans in and gives Armin the softest peck on the lips. They’re both quiet for a second.

“Maybe I should try again?”

He leans in again but this time, he grabs Armin and presses their lips together. When they part, he starts laughing first and then Eren. They both probably look a little crazy, standing underneath the bleachers, laughing.

 

Sixteen and he starts to notice Jean. They’ve never been on good terms, what with Jean constantly picking fights with Eren but Armin has him as a lab partner for biology. They don’t talk much at first but Jean needs all the help he can get with biology. He ends up having to guide Jean through a dissection.

After class, Jean calls out to Armin and offers to buy him lunch. For all his boasting, Jean is unbelievably quiet when he’s alone with Armin, almost shy. Biology becomes more tolerable now that Jean is actually pulling his weight in class. Armin enjoys the company and Jean’s gruff nature. Eren and Mikasa watch Jean like a hawk, part of it is because of their alpha nature and his animosity towards Eren but Armin’s not a child and he’s not bonded to either of them.

By summer, Jean has his first taste of an omega in heat. Armin’s heat is intense, it sometimes gets like this if he’s stressed or nervous. Jean’s not any better, he’s fumbling around anxiously. Armin has to tell him to calm down, once they both start breathing slowly again, it’s a little better.They both sleep well that night.

 

There’s a haze of breakups, getting back together and making out throughout their college years. It’s weird and at the same time, Armin expects it because both him and Jean are just bull-headed. Eren and Mikasa go from overprotective friends to just exasperated. They at least, end up back together in time for graduation. Marco is happy for it, Eren and Mikasa watch carefully. They all graduate, Armin and Mikasa with honours, Eren and Jean with decent marks.

Eren and Mikasa rent a place together, Armin and Jean end up doing the same. Eren and Mikasa are two hours away, it’s the first time they’ve ever been that far apart from each other. He thinks he can handle it, it’s irrational to want to be with them when they’re making a life for themselves, same with him and Jean but it’s tough, the first night he really feels it. Maybe it’s the fact that the three of them were more than just friends, they’re a pack, the closest thing Armin has to a family now that his grandfather’s passed away. They’re also, as much as Armin hates to admit it, his alphas. Not in the traditional sense of the word but they are. Jean holds him tight and while the ache doesn’t quite disappear, it subsides a little.

 

Three years after they’ve moved in and Jean asks him to be his mate. Eren and Mikasa have already made the plunge, Jean may have seen it as an opportunity. They’re at home and not at some fancy restaurant, Armin’s thankful for that. He accepts it and that night they celebrate it.

He’s not supposed to have the mark before he walks down the aisle but Jean had done it on the night he proposed. They were probably a little too drunk for their own good when it had happened. Eren was furious with Jean when he’d seen the mark, they were on a lot better terms now but the three of them were each other’s first. Armin was Eren and Mikasa’s first omega and only omega, it was hard to let go of that.

 

It doesn’t take long before he gets pregnant, he’s been off birth control since they first got engaged. Morning sickness is the worst and he calls in sick when he’s allowed to. His supervisor, Hange takes a keen interest in his pregnancy and prescribes him remedies and medications. Jean scrunches up his nose when he tries some of Hange’s herbal remedies. It must be bad if Jean’s beta nose can actually smell it but it works wonders on his stomach.

He’s expecting twins, it takes Eren a while to adjust to the news that no, Armin isn’t expecting one but two. The girls arrive on May 15, at 1:30 am through induced labor. Their apartment becomes a warzone of unfinished chores and two screaming babies. It’s not easy, the two have a hard time accepting Jean because of his beta scent. They’re happy with Armin, Eren and Mikasa. 

On a particularly trying day, Jean looks like he’s on the verge of tears. Armin puts a hand on his shoulder. Jean gets up and puts Paige in Armin’s hands. 

“They want you.”

He grabs Jean before he can leave.

“Jean, when I mated with you, that meant that we weren’t just two people living together. We’re a pack, Paige and Elise, they’re part of our pack too. It maybe hard because we’re not the textbook pack but we’re still one.”

He puts a half-asleep Paige back in Jean’s arms. She stirs a little but closes her eyes and falls right back to sleep. The next morning, Eren and Mikasa find the two of them sleeping soundly next to Paige and Elise's crib.


End file.
